1. Field of the Invention
The present invention relates to an improved apparatus for retaining a valve body in engagement with the valve neck of a pressurized container. One embodiment in which the present invention is utilized is in conjunction with a valve body which is used to retain a coupling device for tapping a keg of beer which is kept under pressure. In operation, the valve body is inserted by depression into a valve neck which is located at the opening of the container of fluid such as beer. The fluid coupling device is in turn inserted into the valve body by depression and rotation into the valve body. The opening of the container at this location contains a valve neck which is designed to accommodate the valve body and retain it within the neck. Therefore, the coupling device can be securely attached to the valve body so that fluid can be dispensed from the container through the coupler. The field of the present invention relates to the apparatus by which the valve body is effectively retained within the neck portion of the pressurized container.
2. Description of the Prior Art
An apparatus for retaining a valve body with the neck portion of a pressurized container is disclosed in the U.S. Pat. No. 4,181,143 issued to Fallon. The neck portion accommodates the valve body which in turn leads directly to the valve assembly of the container through which fluid is dispensed under pressure from the container into the coupling device and thence out a pouring spout. As shown in U.S. Pat. No. 4,181,143, the top portion of the container neck contains a bushing which has a groove within and extending entirely around the circumference of its inner surface. The groove has an upper and a lower lip which engage the surfaces of a resilient retaining ring which is accommodated within the internal groove of the bushing. The interior portion of the neck further contains a dog legged keyway assembly. The dog legged keyway has a first recessed area which communicates with the top portion of the neck through the upper lip of the groove and further extends to the lower lip. The second offset area forming the dog legged portion communicates with the first recessed area and also extends from the lower lip of the groove to a location below it. The valve body contains a key which is inserted into the first recessed area, then is turned to coincide with the second recessed area and is then depressed so that a retaining ring can be inserted above the valve body and associated key to assure that the key will be kept in place inside the second recessed area. The retaining ring expands to be accommodated within the groove of the bushing in the neck.
While the embodiment disclosed in U.S. Pat. No. 4,181,143 is effective for properly retaining the valve body within the neck, it has a significant disadvantage which could potentially be hazardous to users. The most significant disadvantage of the prior art embodiment is that it permits the retaining apparatus to be tampered with. The retaining ring which is accommodated within the groove and keeps the valve body securely retained within the neck while the container is under pressure, can be removed with a common tool such as a screwdriver. Once the retaining ring is removed, a significant hazard can result from one of two possibilities. Many times, when the valve body is inserted into the valve neck and then turned so that the key on the valve body is aligned with the second recess, a rough or hard turn will cause the key to be broken off. The operator usually doesn't know that the key has been broken off. Once the retaining ring is removed there is nothing left to retain the valve body within the valve housing. Then the pressure within the container could force the valve body to fly out of the neck, thereby potentially seriously injuring someone. Therefore, the embodiment disclosed in the prior art is not tamperproof. While the prior art embodiment is certainly effective under normal use, it does present a serious hazard since it can be easily tampered with.
The present invention significantly modifies the embodiment of the prior art to assure that the valve body is securely retained within the neck of the pressurized container by apparatus means which are tamperproof with common tools. The embodiments of the prior art can be easily tampered with and it is this key element which the present invention addresses.